A 58-year-old man with uncontrolled hypertension presents to the emergency department with sudden onset severe headache, vomiting, and right-sided hemiparesis. Non-contrast CT head shows a hyperdense lesion in the left basal ganglia with intraventricular extension. Which investigation is most appropriate to determine the underlying etiology and guide further management?

Explanation

## Investigation of Choice in Hemorrhagic Stroke with Intraventricular Extension ### Clinical Scenario Analysis The patient presents with acute hypertensive hemorrhagic stroke with intraventricular extension. While non-contrast CT confirms acute hemorrhage, determining the underlying cause is critical for prognosis and management. ### Why CT Angiography (CTA) is Correct **Key Point:** CTA is the investigation of choice to identify secondary causes of hemorrhage, particularly vascular lesions such as: - Cerebral aneurysms - Arteriovenous malformations (AVMs) - Arteriovenous fistulas - Tumor-related bleeding - Vasculitis CTA provides rapid, high-resolution imaging of the cerebral vasculature and can be performed immediately after non-contrast CT without additional patient transfer, making it ideal in acute settings. **High-Yield:** In hemorrhagic stroke with intraventricular extension, CTA should be performed routinely to exclude aneurysmal rupture or other structural vascular lesions, even in patients with a clear hypertensive history. ### Comparison of Investigations | Investigation | Indication | Sensitivity for Aneurysm | Timing | |---|---|---|---| | **CTA** | Rule out secondary causes (aneurysm, AVM) | 95–98% | Immediate, <5 min | | **MRI with GRE** | Chronic hemorrhage, microhemorrhages, subacute phase | Lower in acute phase | 30–60 min, contraindicated if unstable | | **Transcranial Doppler** | Vasospasm detection (post-SAH) | Not diagnostic for source | Bedside, operator-dependent | | **Lumbar puncture** | Xanthochromia confirmation (SAH) | Contraindicated with mass effect/IVH | **Clinical Pearl:** Intraventricular hemorrhage (IVH) extension is a red flag for aneurysmal rupture. Even in hypertensive patients, CTA must be obtained to exclude a secondary structural cause before attributing the bleed solely to hypertension. **Warning:** Lumbar puncture is contraindicated in this patient due to intraventricular hemorrhage and risk of herniation. MRI is time-consuming and not ideal in acute unstable hemorrhage. ### Diagnostic Algorithm ```mermaid flowchart TD A["Acute ICH on NCCT"]:::outcome --> B{"IVH present?"}:::decision B -->|"Yes"| C["CTA to rule out aneurysm/AVM"]:::action B -->|"No"| D{"Hypertensive location?"}:::decision D -->|"Yes, typical location"| E["CTA still recommended"]:::action D -->|"Atypical location"| C C --> F{"Lesion found?"}:::decision F -->|"Aneurysm"| G["Neurosurgery consult, DSA if needed"]:::action F -->|"AVM"| H["Vascular intervention planning"]:::action F -->|"None"| I["Hypertensive ICH, supportive care"]:::outcome ``` [cite:Harrison 21e Ch 296]